248 Scientific Proceeding*, Royal Dublin Society. 



some five or six miles north of Antrim. Grey, granular, durable ; 

 works well. Used for dressings, steps, quoins, piers, &c, in 

 churches, country buildings, and other public structures in almost 

 every town in Antrim." (W. Gray.) 



In the north-east part of the county, in the Ballycastle district 

 (barony of Cary), there are whinstones of Carboniferous age, as also 

 metamorphosed intrusive rocks, associated with the tract of schists 

 (Ordovician or Arenig). These schists and whinstones are very 

 little used, as sandstone occurs in the immediate neighbour- 

 hood. 



A little northward of Cushendun there is a tract of a handsome 

 red elvan, which cuts and polishes well ; but, unfortunately, it is so 

 cut up with joints as to rise in pieces of small dimensions. (A. 

 IP Henry.) 



In the N. E., near Runabay, tbere is a similar elvan , 

 brighter red ; a very handsome stone. (P. Clarke.) 



Associated with the Silurian conglomerates at Cushendall there 

 is a purplish, sometimes lighter-coloured (dove colour), and porphy- 

 ritic euryte intrude. The dove-coloured is a good, durable stone, 

 and has been used throughout in the building of the Coastguard 

 Station. The porphyritic variety ought to cut and polish well, 

 and make a handsome stone. The dark-purplish variety is not 

 approved of. 



NOKTH-EASTEBN IKELAND. 



[Down, Louth, Armagh, Monaghan, Cavan, Longford, "Westmeath, and Meath. 

 N.B. — Antrim, for convenience, is put along with N.W". and N. Ireland.] 



Chronological Account. 



The exotic and metamorphic rocks in this territory seem to 

 belong to the following geological periods : — 



Ordovician and Llandovery — Granite, Elvan, FeMone, Euryte, 

 Whinstone, Tuff, and Metamorphic Rocks. 



Silurian and Devonian (Lower Old Red Sandstone). — The 

 Cavan granite is post- Ordovician and pre-Carboniferous ; it ought, 

 therefore to belong to the Llandovery, or Silurian, or Devonian 

 times, probably Silurian ; but this canDot be positively affirmed. 



